CN109478955A

CN109478955A - A kind of feedback parameter report method and device

Info

Publication number: CN109478955A
Application number: CN201680087697.8A
Authority: CN
Inventors: 张瑞齐; 张荻
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2016-08-11
Filing date: 2016-08-11
Publication date: 2019-03-15
Also published as: WO2018027813A1

Abstract

The application discloses a kind of feedback parameter report method and device, and method includes: that terminal device obtains the antenna configurations configuration parameter that base station issues and orthogonal basis generates control parameter；At least two orthogonal basis are generated according to these parameters, the construction of each orthogonal basis is related with the antenna configurations of base station side；The downlink channel condition information reference signal CSI-RS from base station is received, channel parameter is determined according to CSI-RS；Selection target orthogonal basis；And the channel parameter and target orthogonal basis extract feedback parameter, and are reported to the base station, wherein the number of parameters of the feedback parameter is less than the number of the channel parameter.There are a small amount of amplitude the larger value in vector or matrix after doing projection mapping due to the target orthogonal basis, and then the information such as these amplitude the larger value are reported to base station as feedback parameter, it avoids all reporting all feature vector elements, to reduce the occupied bearing resource of uplink feedback, resource overhead has been saved.

Description

Feedback parameter reporting method and device

Technical Field

The present invention relates to the field of wireless communications technologies, and in particular, to a method and an apparatus for reporting a feedback parameter.

Background

An LTE (Long Term Evolution ) system widely adopts a MIMO (Multiple Input and Multiple Output) technology, and for a user at a cell edge, a Space Frequency Block Code (SFBC) transmission mode is generally adopted to improve a signal-to-noise ratio at the cell edge. For users in the center of the cell, a transmission mode of multi-layer parallel transmission is generally adopted to provide a higher data transmission rate. If the base station obtains all or part of the downlink channel information, Precoding (Precoding) processing can be adopted to improve the signal transmission quality or rate and reduce the feedback load.

In the precoding process, for a TDD (Time Division duplex) system, since the uplink and the downlink of a wireless channel have mutual difference, a downlink precoding weighting vector can be estimated according to the uplink channel. However, for FDD (frequency Division duplex) system, the base station side generally obtains the precoding weight matrix by feeding back the precoding vector through the terminal equipment (abbreviated as UE). For example, in LTE release 10 (rel.10), a two-stage codebook feedback mechanism is defined to achieve the purpose of reducing feedback load.

Generally, the feedback of the precoding vector can be realized by direct quantization or analog feedback, and the difference is that the Channel State Information (CSI) precision is higher by using analog feedback compared with the direct quantization feedback method. Taking analog feedback as an example, in the process of analog feedback, the terminal device performs eigenvalue decomposition on a frequency domain channel (the frequency domain channel may be represented by H) to obtain an eigenvector, wherein the dimension of the eigenvector is proportional to the number of antenna ports on the base station side, modulates each element in the eigenvector onto a sequence, and sends the modulated sequence to the base station.

For example, when the rank of the channel is 1, the dimension of the feature vector may be represented as N_t×1，N_tThe number of antenna ports at the base station side is represented, w (k) is represented as the kth element of the eigenvector, and each element of the eigenvector needs to be reported to the base station when the terminal device feeds back. N generated by terminal equipment_tWhere the mth sequence is denoted Sm, each having a length a, as shown in fig. 1, where a is 12, then one sequence may be carried by one OFDM symbol in one Resource Block (RB), and the kth element in the eigenvector is multiplied by the kth sequence, i.e., w (k) × S_kAnd is carried through one OFDM symbol of one RB. Therefore, when the number of antenna ports on the base station side is large, the number of OFDM symbols required by reporting the feature vector by the terminal equipment is increased, a large amount of uplink resources are consumed, and the uplink resource overhead is large.

Disclosure of Invention

The embodiment of the invention provides a feedback parameter reporting method and a feedback parameter reporting device, which are used for solving the problem that a large amount of uplink resources are consumed for reporting a characteristic vector when the number of antenna ports on a base station side is large.

In a first aspect, an embodiment of the present application provides a method for reporting a feedback parameter, where the method includes:

the method comprises the steps that terminal equipment obtains antenna configuration parameters and orthogonal base generation control parameters issued by a base station; generating at least two orthogonal bases according to the antenna configuration parameters and the orthogonal base generation control parameters, wherein the structure of each orthogonal base is related to the antenna configuration of the base station side; receiving a downlink channel state information reference signal (CSI-RS) from a base station, and determining channel parameters according to the CSI-RS; selecting one of the at least two orthogonal bases as a target orthogonal base according to the channel parameters; and extracting feedback parameters according to the channel parameters and the target orthogonal basis, and reporting the feedback parameters to the base station, wherein the number of the feedback parameters is less than that of the channel parameters.

In the method, a terminal device generates at least two orthogonal bases through an antenna configuration parameter and an orthogonal base generation control parameter issued by a base station, determines a channel parameter according to a downlink channel state information reference signal sent by the base station, and selects a target orthogonal base according to the channel parameter, so that a small number of large-amplitude values exist in a vector or a matrix after the channel parameter is subjected to projection mapping on the target orthogonal base, information such as the large-amplitude values can be extracted from the projection of the channel parameter on the target orthogonal base to serve as feedback parameters, and other small-amplitude values are discarded, so that the number of parameters in reported feedback parameters is smaller than the number of parameters in the downlink channel parameter. The extracted part of the values with larger amplitude or the feedback parameters is reported to the base station, namely the number of the parameters of the feedback parameters is less than that of the channel parameters, so that the bearing resources occupied by the uplink feedback are reduced, and the resource overhead is saved.

In addition, the structure of the selected target orthogonal base is related to the antenna state at the base station side, and the target orthogonal base can enable the projection energy of the channel on the orthogonal base to be more concentrated on a few points, so that the error caused by discarding a value with a smaller amplitude can be reduced, and the feedback accuracy of the terminal equipment is improved.

With reference to the first aspect, in a first implementation of the first aspect, the antenna configuration parameters include at least one of the following parameters: the number of first-dimension antenna ports, the number of second-dimension antenna ports and configuration parameters of base station side polarized antennas; wherein the polarized antenna configuration comprises a single polarized antenna and a dual polarized antenna; the orthogonal basis generation control parameter includes at least one of the following parameters: the number of the first dimension orthogonal bases, the number of the second dimension orthogonal bases and the number of the polarization direction dimension orthogonal bases.

With reference to the first implementation of the first aspect, in a second implementation of the first aspect, if a dual-polarized antenna is used on a base station side, the orthogonal basis is represented as a multiplication of a block diagonal matrix and a first unitary matrix, where each block matrix in the block diagonal matrix is a second unitary matrix, and a dimension of the second unitary matrix is N rows and M columns; the first unitary matrix is expressed as a kronecker product of a third unitary matrix with 2 rows and 2 columns and an identity matrix with M rows and M columns; and if the base station side adopts a single-polarization antenna, the orthogonal base is represented as the second unitary matrix, wherein N represents the number of antenna ports in one polarization direction, and M is less than or equal to N.

With reference to the second implementation of the first aspect, in a third implementation of the first aspect, if an antenna port on a base station side is configured as a two-dimensional antenna port, the second unitary matrix is represented as a kronecker product of a fourth unitary matrix and a fifth unitary matrix; wherein the fourth unitary matrix has a dimension of N₁Line M₁Columns, the dimension of the fifth unitary matrix is N₂Line M₂Column, N₁Representing the number of first dimension antenna ports in one polarization direction, N₂Represents the number of second dimension antenna ports in one polarization direction, and M₁≤N₁,M₂≤N₂。

With reference to the first aspect or any one of the first to third implementations of the first aspect, in a fourth implementation of the first aspect, if a dual-polarized antenna is used on a base station side, the generated one orthogonal base is represented as:

if a single-polarized antenna is adopted on the base station side, the generated orthogonal base is represented as:

wherein, B_(k,l,k'l',m)Represents an orthogonal base with the parameters k, l, k ', l', m, U_kAnd U_k'Respectively represent N₁×M₁Unitary matrix of, V_lAnd V_l'Respectively represent N₂×M₂Unitary matrix of, T_mDenotes a 2 × 2 unitary matrix, I denotes (M)₁M₂)×(M₁M₂) Represents a kronecker multiplication, and k, k' e {0,1, Λ O ∈₁-1},l,l'∈{0,1,Λ O₂-1}，m∈{0,1,Λ O₃-1}，O₁Denotes the number of first-dimension orthogonal bases, O₂Denotes the number of orthogonal bases of the second dimension, O₃The number of orthogonal bases in the polarization direction dimension is shown.

With reference to the fourth implementation of the first aspect, in the fifth implementation of the first aspect,

unitary matrix U_kIs shown as

Unitary matrix V_lIs shown as

Unitary matrix T_mIs shown as

Wherein, represents N_x×N_xOr inverse DFT matrix, i.e. expressed in particular as

Or,

the diagonal matrix is represented, specifically as:

or,

x belongs to {1,2,3}, and k is an integer, k is more than or equal to 0 and less than N_x。

With reference to the first aspect, in a sixth implementation of the first aspect, the selecting, by the terminal device, one of the at least two orthogonal bases as a target orthogonal base according to the channel parameter includes: the terminal equipment projects the channel parameters on each orthogonal basis to generate a projection matrix, and projects the at least two orthogonal bases to generate a group of projection matrices, wherein each projection matrix consists of S elements, the terminal equipment selects L elements with larger values in each projection matrix, and calculates the sum of the selected L elements with larger values; comparing the sums of the calculated L larger element values in all projection matrices, and selecting the projection matrix with the largest sum of the L larger element values as the selected target orthogonal basis.

With reference to the sixth implementation of the first aspect, in a seventh implementation of the first aspect, the projecting, by the terminal device, the channel parameter on each orthogonal basis to generate a projection matrix includes:

the terminal equipment projects the channel parameters on each orthogonal base as follows: e ═ G × B_(k,l,k'l',m)In which B is_(k,l,k'l',m)An orthogonal basis with parameters k, l, k ', l', m, and G represents the channel parameter.

With reference to the first aspect, in an eighth implementation of the first aspect, if the channel parameter is a channel matrix, a dimension of the channel matrix is represented as Nr rows and Nt columns, where Nt represents a total number of antenna ports at a base station side, and Nr represents a total number of antenna ports received by the terminal device; if the channel parameter is a channel correlation matrix, the channel correlation momentThe dimension of the array is represented as Nt rows and Nt columns; if the channel parameter is the eigenvector of the channel matrix, the dimension of the eigenvector is represented as R × N_tWherein R represents the rank of the channel matrix.

With reference to the seventh implementation of the first aspect, in a ninth implementation of the first aspect, after the generating at least two orthogonal bases, the method further includes: the terminal equipment numbers all orthogonal bases; the feedback parameters extracted by the terminal equipment comprise: the number of the target orthogonal base, the corresponding L larger element values in the target orthogonal base, and the position indexes of the L larger element values in the projection matrix.

With reference to the first aspect or any one of the first to ninth implementations of the first aspect, in a tenth implementation of the first aspect, the reporting the feedback parameter to the base station includes: in the feedback parameters, the terminal device reports the number of the target orthogonal base and the position indexes of the L larger element values in the projection matrix in a subframe; the broadband of the whole system is composed of at least two sub-bands, and the terminal equipment reports the L larger element values for each sub-band.

In the method, the orthogonal base index and the selected position index with a larger amplitude value are reported by the broadband, and the position index is suitable for the whole bandwidth, so that too much resource overhead is not added to an LTE system. The CSI of each subband is characterized by L large-amplitude values of the feedback parameters, and does not bring much performance loss.

In a second aspect, an embodiment of the present application provides a downlink access method, where the method is applied to a base station side, and the method includes: the base station sets antenna configuration parameters and orthogonal base generation control parameters, wherein the antenna configuration parameters at least comprise one of the following parameters: the number of first-dimension antenna ports, the number of second-dimension antenna ports and configuration parameters of base station side polarized antennas; the orthogonal basis generation control parameter includes at least one of the following parameters: the number of the first dimension orthogonal bases, the number of the second dimension orthogonal bases and the number of the polarization direction dimension orthogonal bases; and the base station sends the antenna configuration parameters and the orthogonal base generation control parameters to the terminal equipment through static or semi-static signaling.

In this aspect, the base station generates the control parameter by sending the antenna configuration parameter and the orthogonal basis, so that the terminal device can generate a set of orthogonal basis, and further, after the downlink channel parameter is projected on the orthogonal basis, the energy can be concentrated on a few elements. With different orthogonal bases, the energy concentrated on a few elements is different.

With reference to the second aspect, in a first implementation of the first aspect, after the sending, by the base station, the antenna configuration parameter and the orthogonal base generation control parameter, the method further includes: and the base station transmits a downlink channel state information reference signal (CSI-RS) to the terminal equipment, so that the terminal equipment determines channel parameters according to the CSI-RS. And projecting the channel parameters on the orthogonal basis, so that the terminal equipment can selectively report partial large-amplitude values to the base station, thereby avoiding reporting all element values to the base station and increasing the uplink resource overhead.

With reference to the second aspect, in a second implementation of the second aspect, the base station receives a feedback parameter reported by the terminal device, where the feedback parameter includes: the number of the selected target orthogonal basis, L larger element values projected on the target orthogonal basis, and projection position indexes corresponding to the L larger element values; acquiring a target orthogonal base according to the number of the target orthogonal base in the feedback parameters; acquiring L row vectors or L column vectors of the target orthogonal basis according to the projection position indexes corresponding to the L larger element values; and acquiring channel parameters according to the L larger element values and the L row vectors or the L column vectors.

With reference to the second aspect, in a third implementation of the first aspect, after acquiring the channel parameter, the method further includes: and generating a precoding matrix for the terminal equipment according to the channel parameters.

With reference to the second or third implementation manner of the second aspect, in a fourth implementation manner of the second aspect, if a dual-polarized antenna is used on the base station side, the target orthogonal base is represented as:

if a single-polarized antenna is adopted on the base station side, the target orthogonal base is expressed as:

With reference to the second aspect, in a fifth implementation of the second aspect,

unitary matrix U_kIs shown as

Unitary matrix V_lIs shown as

Unitary matrix T_mIs shown as

Or,

the diagonal matrix is represented, specifically as:

or,

With reference to the fifth implementation of the second aspect, in a sixth implementation of the second aspect, if the channel parameter is a channel matrix, a dimension of the channel matrix is represented as N_rLine N_tColumn (i) wherein N_tIndicates the total number of antenna ports on the base station side, N_rRepresenting the total number of antenna ports received by the terminal equipment; if the channel parameter is a channel correlation matrix, the dimension of the channel correlation matrix is represented as N_tLine N_tColumns; if the channel parameter is the eigenvector of the channel matrix, the dimension of the eigenvector is represented as R × N_tWherein R represents the rank of the channel matrix.

In a third aspect, an embodiment of the present application further provides a terminal device, including a receiver, a transmitter, and a processor, where the receiver is configured to obtain an antenna configuration parameter and an orthogonal base generation control parameter sent by a base station; wherein, the antenna configuration parameters at least comprise one of the following parameters: the number of first-dimension antenna ports, the number of second-dimension antenna ports and configuration parameters of base station side polarized antennas; wherein the polarized antenna configuration comprises a single polarized antenna and a dual polarized antenna; the orthogonal basis generation control parameter includes at least one of the following parameters: the number of the first dimension orthogonal bases, the number of the second dimension orthogonal bases and the number of the polarization direction dimension orthogonal bases.

The processor is used for generating at least two orthogonal bases according to the antenna configuration parameters and the orthogonal base generation control parameters, and the construction of each orthogonal base is related to the antenna configuration at the base station side;

the receiver is further configured to receive a downlink channel state information reference signal, CSI-RS, from a base station, and the processor is further configured to determine channel parameters according to the CSI-RS; selecting one of the at least two orthogonal bases as a target orthogonal base according to the channel parameters; extracting feedback parameters according to the channel parameters and the target orthogonal basis;

the transmitter is configured to report the feedback parameters to the base station, where the number of the feedback parameters is smaller than the number of the channel parameters.

With reference to the third aspect, in a first implementation of the third aspect, the processor is further configured to project the channel parameters on each orthogonal basis to generate a projection matrix, and project the at least two orthogonal bases to generate a set of projection matrices, where each projection matrix is composed of S elements, select L elements with larger values in each projection matrix, and calculate a sum of the selected L elements with larger values; comparing the sums of the calculated L larger element values in all projection matrices, and selecting the projection matrix with the largest sum of the L larger element values as the selected target orthogonal basis.

With reference to the first implementation or the second implementation of the third aspect, in a third implementation of the third aspect, the transmitter is specifically configured to report, in a subframe, the number of the target orthogonal base and position indexes of the L larger element values in the projection matrix; and reporting the L larger element values for each sub-band, wherein the broadband of the whole system is composed of at least two sub-bands.

In addition, the terminal device is further configured to implement the first aspect and various implementations of the first aspect.

In a fourth aspect, an embodiment of the present application further provides a base station, including a processor and a transmitter, where the processor is configured to set an antenna configuration parameter and an orthogonal basis generation control parameter, where the antenna configuration parameter includes at least one of the following parameters: the number of first-dimension antenna ports, the number of second-dimension antenna ports and configuration parameters of base station side polarized antennas; the orthogonal basis generation control parameter includes at least one of the following parameters: the number of the first dimension orthogonal bases, the number of the second dimension orthogonal bases and the number of the polarization direction dimension orthogonal bases; and the transmitter is used for transmitting the antenna configuration parameters and the orthogonal basis generation control parameters to the terminal equipment through static or semi-static signaling.

With reference to the fourth aspect, in a first implementation of the fourth aspect, the transmitter is further configured to send a downlink channel state information reference signal CSI-RS to a terminal device, so that the terminal device determines a channel parameter according to the CSI-RS.

With reference to the first implementation of the fourth aspect, in a second implementation of the fourth aspect, the base station further includes a receiver, where the receiver is configured to receive a feedback parameter reported by the terminal device, and the feedback parameter includes: the number of the selected target orthogonal basis, L larger element values projected on the target orthogonal basis, and projection position indexes corresponding to the L larger element values;

the processor is further configured to obtain a target orthogonal base according to a number of the target orthogonal base in the feedback parameter; acquiring L row vectors or L column vectors of the target orthogonal basis according to the projection position indexes corresponding to the L larger element values; and acquiring channel parameters according to the L larger element values and the L row vectors or the L column vectors.

With reference to the fourth aspect, in a third implementation of the fourth aspect, the processor is further configured to generate a precoding matrix for the terminal device according to the channel parameter.

The base station is further configured to implement the second aspect and various implementations of the second aspect.

In a fifth aspect, an embodiment of the present application further provides a computer storage medium, where the computer storage medium may store a program, and when the program is executed, part or all of the steps in each implementation manner of the method and the apparatus for reporting a feedback parameter provided in the present application may be implemented.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a resource block according to an embodiment of the present application;

fig. 2 is a schematic flow chart of a feedback parameter reporting method according to an embodiment of the present application;

fig. 3 is a schematic structural diagram of sub-tape division according to an embodiment of the present application;

fig. 4 is a schematic structural diagram of a dual-polarized antenna provided in an embodiment of the present application;

fig. 5 is a flowchart of another feedback parameter reporting method according to an embodiment of the present application;

fig. 6 is a schematic structural diagram of a terminal device according to an embodiment of the present application;

fig. 7 is a schematic structural diagram of a base station according to an embodiment of the present application;

fig. 8 is a schematic diagram of signal interaction between a base station and a terminal device according to an embodiment of the present application.

Detailed Description

In order to make those skilled in the art better understand the technical solution of the present invention, the technical solution in the embodiment of the present invention will be clearly and completely described below with reference to the drawings in the embodiment of the present invention, and it is obvious that the described embodiment is only a part of the embodiment of the present invention, and not all embodiments.

The technical scheme provided by the application is mainly applied to an LTE system and a 5G system, and the main application scene is the application of a downlink MIMO technology. In a Work formulation stage (Work Item, abbreviated as WI) in LTE release 14, in order to improve the feedback accuracy of downlink channel state information (abbreviated as CSI), an estimated downlink channel or an eigenvector of the downlink channel is fed back to the base station, but when the number of antenna ports on the base station side is large, for example, more than 16 antenna ports, the uplink resource consumed for the terminal device to feed back the eigenvector or matrix of the downlink channel is large.

In order to reduce overhead of uplink resources, embodiments of the present application provide a method and an apparatus for reporting a feedback parameter, which are applied to a terminal device side, and as shown in fig. 2, the method includes the following steps:

step 201: the terminal equipment acquires the antenna configuration parameters and the orthogonal base generation control parameters issued by the base station.

The antenna configuration parameters at least comprise one of the following parameters: the number of first-dimension antenna ports, the number of second-dimension antenna ports and configuration parameters of base station side polarized antennas; wherein the polarized antenna configuration comprises a single polarized antenna and a dual polarized antenna; the orthogonal basis generation control parameter includes at least one of the following parameters: the number of the first dimension orthogonal bases, the number of the second dimension orthogonal bases and the number of the polarization direction dimension orthogonal bases.

Step 202: and the terminal equipment generates at least two orthogonal bases according to the antenna configuration parameters and the orthogonal base generation control parameters, wherein the structure of each orthogonal base is related to the antenna configuration at the base station side.

And generating different expressions of orthogonal bases according to different antenna configuration parameters of the base station side. For example, if a dual-polarized antenna is adopted on the base station side, the orthogonal base is represented by multiplying a block diagonal matrix by a first unitary matrix, wherein each block matrix in the block diagonal matrix is a second unitary matrix, and the dimension of the second unitary matrix is N rows and M columns; the first unitary matrix is expressed as a kronecker product of a third unitary matrix with 2 rows and 2 columns and an identity matrix with M rows and M columns; and if the base station side adopts a single-polarization antenna, the orthogonal base is represented as the second unitary matrix, wherein N represents the number of antenna ports in one polarization direction, and M is less than or equal to N.

Further, if the antenna ports on the base station side are configured as two-dimensional antenna ports, the second unitary matrix is expressed as a kronecker product of a fourth unitary matrix and a fifth unitary matrix; wherein the fourth unitary matrix has a dimension of N₁Line M₁Columns, the dimension of the fifth unitary matrix is N₂Line M₂Column, N₁Representing the number of first dimension antenna ports in one polarization direction, N₂Represents the number of second dimension antenna ports in one polarization direction, and M₁≤N₁,M₂≤N₂。

The orthogonal bases generated by different antenna side configuration parameters are expressed by the following formula:

if a dual-polarized antenna is adopted on the base station side, that is, when P is 2, P represents the polarization direction, the generated orthogonal basis is represented as:

wherein, B_(k,l,k'l',m)Represents an orthogonal base with the parameters k, l, k ', l', m, U_kAnd U_k'Respectively represent N₁×M₁Unitary matrix of, V_lAnd V_l'Respectively represent N₂×M₂Unitary matrix of, T_mRepresenting a 2 x 2 unitary matrix, U_k,V_lAnd T_mAre all unitary matrices, I denotes (M)₁M₂)×(M₁M₂) Represents a kronecker multiplication, and k, k' e {0,1, Λ O ∈₁-1},l,l'∈{0,1,Λ O₂-1}，m∈{0,1,Λ O₃-1}，O₁Representing the number of orthogonal bases of the first dimension，O₂Denotes the number of orthogonal bases of the second dimension, O₃The number of orthogonal bases in the polarization direction dimension is shown.

If a single-polarized antenna is adopted on the base station side, that is, if P is 1, the generated one orthogonal base is represented as:

wherein, B_(k,l,m)Represents an orthogonal base with the parameters k, l, m, U_kRepresents N₁×M₁Unitary matrix of, V_lRepresents N₂×M₂Represents the kronecker product.

Further, the unitary matrix U_kCan be expressed as a unitary matrix V_lCan be expressed as a unitary matrix T_mCan be represented as wherein, represents N_x×N_xThe DFT or inverse DFT matrix of (a) is specifically expressed as:

or,

the diagonal matrix is represented, specifically as:

or,

x belongs to {1,2,3}, and k is an integer, k is more than or equal to 0 and less than N_x. Step 203: the terminal equipment receives a downlink channel state information reference signal (CSI-RS) from a base station and determines channel parameters according to the CSI-RS.

Specifically, if the channel parameter is a channel matrix, the dimension of the channel matrix is represented as N_rLine N_tColumn (i) wherein N_tIndicates the total number of transmitting antenna ports, N, of the base station side_rRepresenting the total number of antenna ports received by said terminal device, further, N_t＝N1×N2×N3。

If the channel parameter is a channel correlation matrix RR, the dimension of the channel correlation matrix is represented as N_tLine N_tColumns; i.e. RR ═ E { H^HH, wherein E {. cndot } represents correlation average, and dimension of RR is represented as N_t×N_t。

If the channel parameter is the eigenvector of the channel matrix, the dimension of the eigenvector is represented as R × N_tWherein R represents the rank of the channel matrix. I.e., W ═ eig (h), where W has dimension R × N_tAnd R represents the rank of the channel.

Step 204: and the terminal equipment selects one of the at least two orthogonal bases as a target orthogonal base according to the channel parameters.

In a specific embodiment, the process of selecting the target orthogonal basis comprises: the terminal equipment projects the channel parameters on each orthogonal basis to generate a projection matrix, projects the at least two orthogonal bases to generate a group of projection matrixes, wherein each projection matrix consists of S elements,

the terminal equipment selects L elements with larger values in each projection matrix, and calculates the sum of the values of the selected L elements with larger values;

comparing the sums of the calculated L larger element values in all projection matrices, and selecting the projection matrix with the largest sum of the L larger element values as the selected target orthogonal basis.

Taking the channel parameter as the feature vector of the downlink channel H as an example, a processing procedure at the terminal device side is described.

The terminal device performs eigenvalue decomposition on the downlink channel H, which can be expressed as: h ═ U Σ V.

Wherein H represents a downlink channel and U represents a dimension N_r×N_rUnitary matrix of (d), representing the dimension N_r×N_tThe diagonal elements of which are eigenvalues of the matrix, V represents N_t×N_tIs used to generate the unitary matrix. According to the RANK R (RANK for short) of the downlink channel matrix, feeding back the eigenvectors corresponding to the R larger eigenvalues to the base station, wherein the eigenvector W can pass through W ═ col (V)^H) Is shown, wherein, col (V)^H) Representing R column vectors, V, corresponding to R larger eigenvalues^HRepresenting the conjugate transpose of matrix V.

Projecting the characteristic vector W to the at least two orthogonal bases to generate a group of projection matrixes, wherein each projection matrix consists of S elements, L elements with larger values are selected from each projection matrix, and the sum of the values of the L selected elements with larger values is calculated; comparing the sums of the calculated L larger element values in all projection matrices, and selecting the projection matrix with the largest sum of the L larger element values as the selected target orthogonal basis, or as the optimal orthogonal basis.

The terminal equipment selects a target orthogonal base from a group of orthogonal bases according to the characteristic vector W, namely the target orthogonal base enables more energy to be concentrated on a few points in the projection of the characteristic vector W on the orthogonal base. That is, the terminal equipment determines the feedback parameters k, k 'l, l'm in the orthogonal basis according to the characteristic vector W, thereby obtaining the target orthogonal basis B_(k,l,k'l',m)。

Step 205: and the terminal equipment extracts feedback parameters according to the channel parameters and the target orthogonal base and reports the feedback parameters to the base station, wherein the number of the feedback parameters is less than that of the channel parameters.

After the terminal equipment selects the target orthogonal base, the channel parameter G is projected to the target orthogonal base,

E＝G×B_(k,l,k'l',m)

wherein B is_(k,l,k'l',m)An orthogonal basis with parameters k, l, k ', l', m, and G represents the channel parameter. E represents a projection matrix, the dimensions of which are denoted R × N_tAnd L large-amplitude values exist in the projection matrix E, and the position index of the L large-amplitude values in the projection matrix E is represented as I_L＝[i₀ L i_L-1]。

Further, after the step 202, numbering all the generated orthogonal bases is also included.

The feedback parameters extracted in step 205 include: the number of the target orthogonal base, the corresponding L larger element values in the target orthogonal base, and the position index I of the L larger element values in the projection matrix_L。

Furthermore, the L larger values may be reported to the base station in an analog feedback manner, or may be reported to the base station in a direct quantization manner.

In the embodiment of the application, the terminal device generates at least two orthogonal bases through an antenna configuration parameter and an orthogonal base generation control parameter issued by a base station, the orthogonal bases are used for concentrating the energy of a downlink channel parameter on a few elements, the channel parameter is determined according to a downlink channel state information reference signal sent by the base station, and a target orthogonal base is selected according to the channel parameter, so that a small number of large-amplitude values exist in a vector or a matrix of the channel parameter after projection mapping on the target orthogonal base, and then the information such as the large-amplitude values can be extracted from the target orthogonal base to be used as feedback parameters, and the rest of small-amplitude values are discarded, so that the parameters in the reported feedback parameters are less than the parameters in the channel parameter. The extracted part of the values with larger amplitude or the feedback parameters is reported to the base station, namely the number of the parameters of the feedback parameters is less than that of the channel parameters, so that the bearing resources occupied by the uplink feedback are reduced, and the resource overhead is saved.

In the above example, reporting the feedback parameter to the base station includes:

in the feedback parameters, the terminal device reports the number of the target orthogonal base and the position indexes of the L larger element values in the projection matrix in a subframe; the broadband of the whole system is composed of at least two sub-bands, and the terminal equipment reports the L larger element values for each sub-band.

Specifically, in the LTE system, the bandwidth of the entire LTE system is composed of a plurality of subbands, and in order to reduce the complexity of uplink feedback, the terminal device selects a target orthogonal base and L index positions with larger values for the bandwidth of the entire LTE system; and on each sub-band, projecting the channel parameter G of the corresponding sub-band on the selected target orthogonal base, selecting the value of the projection of the sub-band G on the L position indexes, and reporting the larger value of each sub-band to the base station.

As shown in fig. 3, a schematic diagram of a subband division structure is shown, and a bandwidth of an LTE system is set to be 10 MHz. The system bandwidth is divided into 9 sub-bands. And the terminal equipment estimates a channel according to the CSI-RS issued by the base station. According to the estimated channel, the terminal device selects an optimal orthogonal base B, i.e. a target orthogonal base, in other words, the target orthogonal base B is suitable for the whole system bandwidth of 10 MHz.

The terminal equipment decomposes the channel on each sub-band into characteristic values to obtain characteristic vectors W1, W2 and … W9, and projects W1-W9 on a target orthogonal base B respectively, namely E1 is W1B; e2 ═ W2 × B, …. In E1, E2, … … E9, L larger values are respectively selected from the 9 values, wherein the positions of the selected L values are the same for E1, E2, … … and E9, so that the position indexes of the L values are applicable to the whole system bandwidth of 10 MHz.

The terminal device selects L larger values from each of Ex, x ═ 1,2, … 9, and reports 9 × L values to the base station, so that the L larger values are calculated based on the subbands.

In this embodiment, for the feedback parameter, the number of the orthogonal base and the position index with a larger selected amplitude are reported by the broadband, and since the position index is suitable for the whole bandwidth, too much resource overhead is not added to the LTE system. The CSI of each subband is characterized by L larger amplitude values of the feedback parameters, so that the performance loss of feedback is further reduced.

For the base station side, the present application also provides a downlink access method, which is located before the step 201, and specifically includes the following steps:

the base station sets antenna configuration parameters and orthogonal base generation control parameters.

The antenna configuration parameters comprise: number of first dimension antenna ports, available N₁Represents; number of second dimension antenna ports, available N₂Represents; and base station side polarized antenna configuration parameters, available N₃Represents; wherein the polarized antenna configuration comprises a single polarized antenna and a dual polarized antenna; for example, let N₃When 1, it means that the polarized antenna is configured as a single polarized antenna, N₃When 2, it means that the polarized antenna is configured as a dual polarized antenna. What is needed isThe orthogonal basis generation control parameters include: number of orthogonal bases of first dimension, available as O₁Represents; number of orthogonal bases in second dimension, available as O₂Represents; and the number of orthogonal bases of the polarization direction dimension, O₃And (4) showing.

And the base station sends the set antenna configuration parameters and the orthogonal base generation control parameters to the terminal equipment in a static or semi-static signaling mode.

And the base station transmits the number of the orthogonal bases to be selected to the terminal equipment through the configuration parameters. For example, for a down-array antenna structure, the base station needs to count the number of antenna ports N in the horizontal dimension and the same polarization direction₁Number of antenna ports N co-polarized with vertical dimension₂And polarization dimension N of the antenna₃And issuing the data to the terminal equipment. And selecting the number of orthogonal bases to be selected in the horizontal direction, the vertical direction and the polarization direction so that the terminal equipment receives the antenna configuration parameters and the orthogonal base generation control parameters, and generating at least two orthogonal bases according to the antenna configuration parameters and the orthogonal base generation control parameters, wherein the structure of each orthogonal base is related to the antenna shape of the base station side.

Fig. 4 is a schematic structural diagram of a dual-polarized antenna, showing an antenna structure in a dual-polarization direction. The antenna is in the form of a dual-polarized antenna, i.e. N₃In each polarization direction, assuming that the first dimension is a horizontal dimension, the number of antenna ports in the same polarization direction in the first dimension is 4, that is, N₁4. The second dimension is a vertical dimension, and the number of antenna ports in the same polarization direction in the second dimension is 2, i.e. N₂2; the total number of the dual-polarized antenna ports is N_t＝N₁N₂N₃。

The static mode is as follows: the base station issues the antenna port configuration parameters and the orthogonal base generation Control parameters to the terminal through Radio Resource Control (RRC) signaling. The parameters are not changed after being issued to the terminal equipment terminal, and the parameters are called as a static configuration mode; if the base station changes the configuration and control parameters again through RRC signaling after a period of time, the configuration mode is called a semi-static configuration mode.

Further, after the base station sends the antenna configuration parameter and the orthogonal base generation control parameter, the method further includes:

and the base station transmits a downlink channel state information reference signal (CSI-RS) to the terminal equipment, so that the terminal equipment determines channel parameters according to the CSI-RS. The base station sends the CSI-RS to the terminal equipment at a certain time, for example, after receiving a feedback signal of a group of orthogonal bases generated by the terminal equipment.

In this embodiment, the base station issues the CSI-RS to the terminal device, so that the terminal device can extract the feedback parameters according to the channel parameters and the target orthogonal base, thereby reporting part of the parameters to the base station, reducing the overhead of uplink resources due to a large number of antenna ports on the base station side, and avoiding that the existing terminal device reports all eigenvectors or the number of antenna ports to the terminal device.

Further, receiving a feedback parameter reported by the terminal device, where the feedback parameter includes: the number of the selected target orthogonal basis, L larger element values projected on the target orthogonal basis, and projection position indexes corresponding to the L larger element values;

acquiring a target orthogonal base according to the number of the target orthogonal base in the feedback parameters; acquiring L row vectors or L column vectors of the target orthogonal basis according to the projection position indexes corresponding to the L larger element values; and acquiring channel parameters according to the L larger element values and the L row vectors or the L column vectors.

In the above embodiment, after acquiring the channel parameter, the method further includes: and generating a precoding matrix for the terminal equipment according to the channel parameters, applying the precoding matrix to a data channel, and issuing CSI-RS for the terminal equipment.

Further, if the base station side employs a dual-polarized antenna, the target orthogonal base is represented as:

wherein, B_(k,l,k'l',m)Represents an orthogonal base with the parameters k, l, k ', l', m, U_kAnd U_k'Respectively represent N₁×M₁Unitary matrix of, V_lAnd V_l'Respectively represent N₂×M₂Unitary matrix of, T_mDenotes a 2 × 2 unitary matrix, I denotes (M)₁M₂)×(M₁M₂) Represents a kronecker multiplication, and k, k' e {0,1, Λ O ∈₁-1},l,l'∈{0,1,ΛO₂-1}，m∈{0,1,ΛO₃-1}，O₁Denotes the number of first-dimension orthogonal bases, O₂Denotes the number of orthogonal bases of the second dimension, O₃The number of orthogonal bases in the polarization direction dimension is shown.

Wherein, the unitary matrix U_kIs shown as

Unitary matrix V_lIs shown as

Unitary matrix T_mIs shown as

Or,

the diagonal matrix is represented, specifically as:

or,

The matrix or expression provided herein is only one expression of the orthogonal basis provided herein, including but not limited to the above expressions, and other expressions or formulas are possible.

Further, if the channel parameter is a channel matrix, the dimension of the channel matrix is represented as N_rLine N_tColumn (i) wherein N_tIndicates the total number of antenna ports on the base station side, N_rRepresenting the total number of antenna ports received by the terminal equipment; if the channel parameter is a channel correlation matrix, the dimension of the channel correlation matrix is represented as N_tLine N_tColumns; if the channel parameter is the eigenvector of the channel matrix, the dimension of the eigenvector is represented as R × N_tWherein R represents the rank of the channel matrix.

In another specific embodiment, the process of generating and forwarding the feedback parameter between the base station and the terminal device includes:

step 501: the base station sets antenna configuration parameters and orthogonal base generation control parameters;

step 502: the base station sends the antenna configuration parameters and the orthogonal base generation control parameters to the terminal equipment;

step 503: the terminal equipment receives the parameters and generates a group of orthogonal bases according to the parameters, wherein the group of orthogonal bases comprises at least two orthogonal bases, the structure of each orthogonal base is related to the antenna shape of the base station side, the antenna shape is a single-polarization antenna and a dual-polarization antenna, and the number of antenna ports corresponding to different polarization antennas is different;

step 504: the base station transmits CSI-RS to the terminal equipment;

step 505: the terminal equipment receives the CSI-RS from the base station and determines channel parameters according to the CSI-RS;

step 506: the terminal equipment selects one of the at least two orthogonal bases as a target orthogonal base according to the channel parameters, so that a small number (L) of large-amplitude values exist in a characteristic vector or a matrix after the target orthogonal base is mapped, and the rest values are small-amplitude values.

Step 507: the terminal equipment extracts feedback parameters according to the channel parameters and the target orthogonal base, wherein the number of the parameters of the feedback parameters is smaller than the number of the channel parameters, namely the number of antenna ports at the base station side contained in the reported feedback parameters is smaller than the number of antenna ports contained in the channel parameters; the feedback parameters include: the number of the target orthogonal base, the corresponding L larger element values in the target orthogonal base, and the position indexes of the L larger element values in the projection matrix.

Step 508: and reporting the feedback parameters to the base station.

Step 508 is followed by: the base station receives the feedback parameters reported by the terminal equipment and acquires the target orthogonal base according to the number of the target orthogonal base in the feedback parameters; acquiring L row vectors or L column vectors of the target orthogonal basis according to the projection position indexes corresponding to the L larger element values; and acquiring channel parameters according to the L larger element values and the L row vectors or the L column vectors. And generating a precoding matrix for the terminal equipment according to the channel parameters.

The embodiment of the method has the following beneficial effects:

firstly, a base station generates a control parameter by sending an antenna configuration parameter and an orthogonal base, so that a terminal device can generate a group of orthogonal bases, and then a characteristic vector of a downlink channel is divided into values with different sizes.

Secondly, the terminal equipment selects a target orthogonal base from the generated orthogonal bases through the CSI-RS, more energy is concentrated on a few positions after the characteristic vector or a downlink channel is mapped due to the target orthogonal base, namely a few values with larger amplitudes are extracted and reported, and other values with smaller amplitudes are abandoned by extracting and reporting feedback parameters such as the small values with larger amplitudes, so that each element of the characteristic vector is prevented from being reported to a base station, the overhead of uplink feedback is reduced, and the performance loss caused by the abandoned value with smaller amplitude can be reduced.

And thirdly, reporting the orthogonal base index and the position index with the larger selected amplitude value by the broadband, wherein the position index is suitable for the whole bandwidth, so that too much resource overhead can not be added to the LTE system. The CSI of each subband is characterized by L large-amplitude values of the feedback parameters, and does not bring much performance loss.

In another embodiment of the present application, a terminal device is further provided, where as shown in fig. 6, corresponding to the embodiment of the feedback parameter reporting method, the terminal device 600 includes: a receiving unit 601, a processing unit 602 and a transmitting unit 603.

A receiving unit 601, configured to obtain an antenna configuration parameter and an orthogonal base generation control parameter sent by a base station; the antenna configuration parameters at least comprise one of the following parameters: the number of first-dimension antenna ports, the number of second-dimension antenna ports and configuration parameters of base station side polarized antennas; wherein the polarized antenna configuration comprises a single polarized antenna and a dual polarized antenna; the orthogonal basis generation control parameter includes at least one of the following parameters: the number of the first dimension orthogonal bases, the number of the second dimension orthogonal bases and the number of the polarization direction dimension orthogonal bases.

A processing unit 602, configured to generate at least two orthogonal bases according to the antenna configuration parameters and orthogonal base generation control parameters, where a structure of each orthogonal base is related to an antenna configuration at a base station side;

further, if a dual-polarized antenna is adopted on the base station side, the orthogonal base is represented by multiplying a block diagonal matrix by a first unitary matrix, wherein each block matrix in the block diagonal matrix is a second unitary matrix, and the dimensionality of the second unitary matrix is N rows and M columns; the first unitary matrix is expressed as a kronecker product of a third unitary matrix with 2 rows and 2 columns and an identity matrix with M rows and M columns;

and if the base station side adopts a single-polarization antenna, the orthogonal base is represented as the second unitary matrix, wherein N represents the number of antenna ports in one polarization direction, and M is less than or equal to N.

If the antenna port on the base station side is configured to be a two-dimensional antenna port, the second unitary matrix is expressed as a kronecker product of a fourth unitary matrix and a fifth unitary matrix; wherein the fourth unitary matrix has a dimension of N₁Line M₁Columns, the dimension of the fifth unitary matrix is N₂Line M₂Column, N₁Representing the number of first dimension antenna ports in one polarization direction, N₂Represents the number of second dimension antenna ports in one polarization direction, and M₁≤N₁,M₂≤N₂。

A receiving unit 601, configured to receive a downlink channel state information reference signal CSI-RS from a base station;

a processing unit 602, further configured to determine channel parameters according to the CSI-RS; the device is used for selecting one of the at least two orthogonal bases as a target orthogonal base according to the channel parameters; extracting feedback parameters according to the channel parameters and the target orthogonal basis,

the sending unit 603 is further configured to report the feedback parameters to the base station, where the number of the feedback parameters is smaller than the number of the channel parameters.

Further, the processing unit 602 is further configured to number all orthogonal bases;

the feedback parameters extracted by the terminal equipment comprise: the number of the target orthogonal base, the corresponding L larger element values in the target orthogonal base, and the position indexes of the L larger element values in the projection matrix.

Further, if the base station side employs a dual-polarized antenna, the generated one orthogonal base is represented as:

wherein, B_(k,l,k'l',m)Represents an orthogonal base with the parameters k, l, k ', l', m, U_kAnd U_k'Respectively represent N₁×M₁Unitary matrix of, V_lAnd V_l'Respectively represent N₂×M₂Unitary matrix of, T_mRepresenting a 2 x 2 unitary matrix, U_k,V_lAnd T_mAre all unitary matrices, I denotes (M)₁M₂)×(M₁M₂) Represents a kronecker multiplication, and k, k' e {0,1, Λ O ∈₁-1},l,l'∈{0,1,Λ O₂-1}，m∈{0,1,Λ O₃-1}，O₁Denotes the number of first-dimension orthogonal bases, O₂Denotes the number of orthogonal bases of the second dimension, O₃The number of orthogonal bases in the polarization direction dimension is shown.

And, the unitary matrix U_kIs shown as

The unitary matrix V_lIs shown as

The unitary matrix T_mIs shown as

Or,

the diagonal matrix is represented, specifically as:

or,

Further, the processing unit 602 is specifically configured to:

projecting the channel parameters on each orthogonal basis to generate a projection matrix, projecting the at least two orthogonal bases to generate a group of projection matrices, wherein each projection matrix consists of S elements,

selecting L elements with larger values in each projection matrix, and calculating the sum of the values of the selected L elements with larger values;

Further, projecting the channel parameters on each of the orthogonal bases is represented as:

E＝G×B_(k,l,k'l',m)

wherein B is_(k,l,k'l',m)An orthogonal basis with parameters k, l, k ', l', m, and G represents the channel parameter.

Further, if the channel parameter is a channel matrix, the dimension of the channel matrix is represented as N_rLine N_tColumn (i) wherein N_tIndicates the total number of antenna ports on the base station side, N_rRepresenting the total number of antenna ports received by the terminal equipment;

if the channel parameter is a channel correlation matrix, the dimension of the channel correlation matrix is represented as N_tLine N_tColumns;

if the channel parameter is the eigenvector of the channel matrix, the dimension of the eigenvector is represented as R × N_tWherein R represents the rank of the channel matrix.

Further, the sending unit 603 is further configured to, in the feedback parameter, report, by the terminal device, the number of the target orthogonal base and the position indexes of the L larger element values in the projection matrix in one subframe; the wideband of the whole system is composed of at least two sub-bands, and the L larger element values are reported for each sub-band.

In order to reduce the overhead of uplink feedback, the terminal device provided in the embodiment of the present application maps the vector or matrix representing the downlink channel on the target orthogonal basis, so that a small number of large amplitude values exist in the mapped vector or matrix, and the remaining small amplitude values are discarded. In addition, the structure of the selected target orthogonal base is related to the antenna shape of the base station end, and one target orthogonal base can enable the projection of the channel on the orthogonal base to be concentrated on a few points, so that the error caused by discarding smaller amplitude values is reduced.

In another embodiment of the present application, there is also provided a base station, as shown in fig. 7, including: a receiving unit 701, a processing unit 702 and a transmitting unit 703,

a processing unit 702, configured to set an antenna configuration parameter and an orthogonal basis generation control parameter, where the antenna configuration parameter at least includes one of the following parameters: the number of first-dimension antenna ports, the number of second-dimension antenna ports and configuration parameters of base station side polarized antennas; the orthogonal basis generation control parameter includes at least one of the following parameters: the number of the first dimension orthogonal bases, the number of the second dimension orthogonal bases and the number of the polarization direction dimension orthogonal bases.

A sending unit 703, configured to send the antenna configuration parameter and the orthogonal basis generation control parameter to a terminal device through a static or semi-static signaling.

Further, the sending unit 703 is further configured to send a downlink channel state information reference signal CSI-RS to the terminal device, so that the terminal device determines the channel parameter according to the CSI-RS.

The receiving unit 701 is configured to receive a feedback parameter reported by the terminal device, where the feedback parameter includes: the number of the selected target orthogonal basis, L larger element values projected on the target orthogonal basis, and projection position indexes corresponding to the L larger element values;

the processing unit 702 is further configured to obtain a target orthogonal base according to a number of the target orthogonal base in the feedback parameter; acquiring L row vectors or L column vectors of the target orthogonal basis according to the projection position indexes corresponding to the L larger element values; and acquiring channel parameters according to the L larger element values and the L row vectors or the L column vectors.

In addition, after acquiring the channel parameters, the method further comprises: the processing unit 702 is further configured to generate a precoding matrix for the terminal device according to the channel parameter, and apply the precoding matrix to a data channel.

Further, the terminal device provided in this embodiment corresponds to the embodiment of the downlink access method, and therefore, the processing unit, the receiving unit, and the sending unit are further configured to implement all or part of the steps in the downlink access method.

In the embodiment of specific hardware, a schematic diagram of signal interaction between a base station and a terminal device is shown in fig. 8. Corresponding to the embodiments of the feedback parameter reporting method and the downlink access method, each base station and each terminal device include: a receiver, a processor, and a transmitter.

The receiver functions as a receiving unit, the processor functions as a processing unit, and the transmitter functions as a transmitting unit, and each processor further includes a memory.

Further, the processor may be a general purpose Central Processing Unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits for controlling the execution of programs according to the present invention.

The Memory may be, but is not limited to, a Read-Only Memory (ROM) or other type of static storage device that can store static information and instructions, a Random Access Memory (RAM) or other type of dynamic storage device that can store information and instructions, an Electrically Erasable Programmable Read-Only Memory (EEPROM), a Compact Disc Read-Only Memory (CD-ROM) or other optical Disc storage, optical Disc storage (including Compact Disc, laser Disc, optical Disc, digital versatile Disc, blu-ray Disc, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. The memory may be separate or integrated with the processor. Wherein the memory is used for storing application program codes for executing the scheme of the invention and is controlled by the processor to execute. The processor is configured to execute application program code stored in the memory.

In addition, the processor in the base station side further includes a setting unit, and the setting unit is configured to set an antenna configuration parameter and an orthogonal base generation control parameter, where the antenna configuration parameter at least includes one of the following parameters: the number of first-dimension antenna ports, the number of second-dimension antenna ports and configuration parameters of base station side polarized antennas; the orthogonal basis generation control parameter includes at least one of the following parameters: the number of the first dimension orthogonal bases, the number of the second dimension orthogonal bases and the number of the polarization direction dimension orthogonal bases.

The terminal device is configured to implement all or part of the functions of the feedback parameter reporting method in the foregoing embodiment, and the base station is configured to implement all or part of the functions of a downlink access method in the foregoing embodiment.

The terminal equipment comprises User Equipment (UE), a user terminal, a client and the like. Specifically, the terminal device further includes: a mobile phone, a tablet computer, a palm computer or a mobile internet device.

"unit" in the above embodiments may refer to an application-specific integrated circuit (ASIC), a circuit, a processor and memory that execute one or more software or firmware programs, an integrated logic circuit, and/or other devices that may provide the above functionality.

An embodiment of the present invention further provides a computer storage medium, configured to store computer software instructions for the feedback parameter reporting method or the downlink access method shown in fig. 6 or fig. 7, where the computer software instructions include a program designed to execute the method according to the embodiment of the present invention. The transmission of the feedback parameters may be achieved by executing a stored program.

While the invention has been described in connection with various embodiments, other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a review of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the word "a" or "an" does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, apparatus (device), or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein. A computer program stored/distributed on a suitable medium supplied together with or as part of other hardware, may also take other distributed forms, such as via the Internet or other wired or wireless telecommunication systems.

The present invention has been described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (devices) and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

While the invention has been described in conjunction with specific features and embodiments thereof, it will be evident that various modifications and combinations can be made thereto without departing from the spirit and scope of the invention. Accordingly, the specification and figures are merely exemplary of the invention as defined in the appended claims and are intended to cover any and all modifications, variations, combinations, or equivalents within the scope of the invention. It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

A method for reporting feedback parameters is characterized in that the method comprises the following steps:

the method comprises the steps that terminal equipment obtains antenna configuration parameters and orthogonal base generation control parameters issued by a base station;

the terminal equipment generates at least two orthogonal bases according to the antenna configuration parameters and the orthogonal base generation control parameters, and the structure of each orthogonal base is related to the antenna configuration at the base station side;

the method comprises the steps that terminal equipment receives a downlink channel state information reference signal (CSI-RS) from a base station and determines channel parameters according to the CSI-RS;

the terminal equipment selects one of the at least two orthogonal bases as a target orthogonal base according to the channel parameters;

and the terminal equipment extracts feedback parameters according to the channel parameters and the target orthogonal base and reports the feedback parameters to the base station, wherein the number of the feedback parameters is less than that of the channel parameters.
The method of claim 1,

the antenna configuration parameters at least comprise one of the following parameters: the number of first-dimension antenna ports, the number of second-dimension antenna ports and configuration parameters of base station side polarized antennas; wherein the polarized antenna configuration comprises a single polarized antenna and a dual polarized antenna;

the orthogonal basis generation control parameter includes at least one of the following parameters: the number of the first dimension orthogonal bases, the number of the second dimension orthogonal bases and the number of the polarization direction dimension orthogonal bases.
The method of claim 2,

if a base station side adopts a dual-polarized antenna, the orthogonal base is represented by multiplying a block diagonal matrix by a first unitary matrix, wherein each block matrix in the block diagonal matrix is a second unitary matrix, and the dimensionality of the second unitary matrix is N rows and M columns; the first unitary matrix is expressed as a kronecker product of a third unitary matrix with 2 rows and 2 columns and an identity matrix with M rows and M columns;

and if the base station side adopts a single-polarization antenna, the orthogonal base is represented as the second unitary matrix, wherein N represents the number of antenna ports in one polarization direction, and M is less than or equal to N.
The method of claim 3,

if the antenna port on the base station side is configured to be a two-dimensional antenna port, the second unitary matrix is expressed as a kronecker product of a fourth unitary matrix and a fifth unitary matrix; wherein the fourth unitary matrix has a dimension of N₁Line M₁Columns, the dimension of the fifth unitary matrix is N₂Line M₂Column, N₁Representing the number of first dimension antenna ports in one polarization direction, N₂Represents the number of second dimension antenna ports in one polarization direction, and M₁≤N₁,M₂≤N₂。
The method according to any one of claims 1 to 4,

if the base station side adopts a dual-polarized antenna, the generated orthogonal base is represented as:

if a single-polarized antenna is adopted on the base station side, the generated orthogonal base is represented as:

wherein, B_(k,l,k'l',m)Represents an orthogonal base with the parameters k, l, k ', l', m, U_kAnd U_k'Respectively represent N₁×M₁Unitary matrix of, V_lAnd V_l'Respectively represent N₂×M₂Unitary matrix of, T_mDenotes a 2 × 2 unitary matrix, I denotes (M)₁M₂)×(M₁M₂) Represents a kronecker multiplication, and k, k' e {0,1, Λ O ∈₁-1},l,l'∈{0,1,ΛO₂-1}，m∈{0,1,ΛO₃-1}，O₁Denotes the number of first-dimension orthogonal bases, O₂Denotes the number of orthogonal bases of the second dimension, O₃The number of orthogonal bases in the polarization direction dimension is shown.
The method of claim 5,

unitary matrix U_kIs shown as

Unitary matrix V_lIs shown as

Unitary matrix T_mIs shown as

Wherein, represents N_x×N_xOr inverse DFT matrix, i.e. expressed in particular as

Or,

the diagonal matrix is represented, specifically as:

or,

x belongs to {1,2,3}, and k is an integer, k is more than or equal to 0 and less than N_x。
The method of claim 1, wherein selecting, by the terminal device, one of the at least two orthogonal bases as the target orthogonal base according to the channel parameter comprises:

the terminal equipment projects the channel parameters on each orthogonal basis to generate a projection matrix, projects the at least two orthogonal bases to generate a group of projection matrices, wherein each projection matrix consists of S elements,

the terminal equipment selects L elements with larger values in each projection matrix, and calculates the sum of the values of the selected L elements with larger values;

comparing the sums of the calculated L larger element values in all projection matrices, and selecting the projection matrix with the largest sum of the L larger element values as the selected target orthogonal basis.
The method of claim 7, wherein the terminal device projecting the channel parameters on each of the orthogonal bases to generate a projection matrix comprises:

the terminal equipment projects the channel parameters on each orthogonal base as follows:

E＝G×B_(k,l,k'l',m)

wherein B is_(k,l,k'l',m)An orthogonal basis with parameters k, l, k ', l', m, and G represents the channel parameter.
The method of claim 1,

if the channel parameter is a channel matrix, the dimension of the channel matrix is represented as N_rLine N_tColumn (i) wherein N_tIndicates the total number of antenna ports on the base station side, N_rRepresenting the total number of antenna ports received by the terminal equipment;

if the channel parameter is a channel correlation matrix, the dimension of the channel correlation matrix is represented as N_tLine N_tColumns;

if the channel parameter is the eigenvector of the channel matrix, the dimension of the eigenvector is represented as R × N_tWherein R represents the rank of the channel matrix.
The method of claim 7, further comprising, after generating at least two orthogonal bases: the terminal equipment numbers all orthogonal bases;

the feedback parameters extracted by the terminal equipment comprise: the number of the target orthogonal base, the corresponding L larger element values in the target orthogonal base, and the position indexes of the L larger element values in the projection matrix.
The method according to any of claims 1-10, wherein reporting the feedback parameters to the base station comprises:

in the feedback parameters, the terminal device reports the number of the target orthogonal base and the position indexes of the L larger element values in the projection matrix in a subframe;

the broadband of the whole system is composed of at least two sub-bands, and the terminal equipment reports the L larger element values for each sub-band.
A downlink access method is characterized in that the method comprises the following steps:

the base station sets antenna configuration parameters and orthogonal base generation control parameters, wherein the antenna configuration parameters at least comprise one of the following parameters: the number of first-dimension antenna ports, the number of second-dimension antenna ports and configuration parameters of base station side polarized antennas; the orthogonal basis generation control parameter includes at least one of the following parameters: the number of the first dimension orthogonal bases, the number of the second dimension orthogonal bases and the number of the polarization direction dimension orthogonal bases;

and the base station sends the antenna configuration parameters and the orthogonal base generation control parameters to the terminal equipment through static or semi-static signaling.
The method of claim 12, wherein after the base station sends the antenna configuration parameters and the orthogonal basis generation control parameters, the method further comprises:

and the base station transmits a downlink channel state information reference signal (CSI-RS) to the terminal equipment, so that the terminal equipment determines channel parameters according to the CSI-RS.
The method of claim 12, further comprising:

receiving feedback parameters reported by the terminal equipment, wherein the feedback parameters comprise: the number of the selected target orthogonal basis, L larger element values projected on the target orthogonal basis, and projection position indexes corresponding to the L larger element values;

acquiring a target orthogonal base according to the number of the target orthogonal base in the feedback parameters;

acquiring L row vectors or L column vectors of the target orthogonal basis according to the projection position indexes corresponding to the L larger element values;

and acquiring channel parameters according to the L larger element values and the L row vectors or the L column vectors.
The method of claim 14, wherein obtaining the channel parameters further comprises: and generating a precoding matrix for the terminal equipment according to the channel parameters.
The method according to claim 14 or 15,

if the base station side adopts a dual-polarized antenna, the target orthogonal base is expressed as:

if a single-polarized antenna is adopted on the base station side, the target orthogonal base is expressed as:

wherein, B_(k,l,k'l',m)Represents an orthogonal base with the parameters k, l, k ', l', m, U_kAnd U_k'Respectively represent N₁×M₁Unitary matrix of, V_lAnd V_l'Respectively represent N₂×M₂Unitary matrix of, T_mDenotes a 2 × 2 unitary matrix, I denotes (M)₁M₂)×(M₁M₂) Represents a kronecker multiplication, and k, k' e {0,1, Λ O ∈₁-1},l,l'∈{0,1,ΛO₂-1}，m∈{0,1,ΛO₃-1}，O₁Denotes the number of first-dimension orthogonal bases, O₂Denotes the number of orthogonal bases of the second dimension, O₃The number of orthogonal bases in the polarization direction dimension is shown.
The method of claim 16,

unitary matrix U_kIs shown as

Unitary matrix V_lIs shown as

Unitary matrix T_mIs shown as

Wherein, represents N_x×N_xOr inverse DFT matrix, i.e. expressed in particular as

Or,

the diagonal matrix is represented, specifically as:

or,

x belongs to {1,2,3}, and k is an integer, k is more than or equal to 0 and less than N_x。
The method of claim 14,

if the channel parameter is a channel matrix, the dimension of the channel matrix is represented as N_rLine N_tColumn (i) wherein N_tIndicates the total number of antenna ports on the base station side, N_rTo representThe total number of antenna ports received by the terminal equipment;

if the channel parameter is a channel correlation matrix, the dimension of the channel correlation matrix is represented as N_tLine N_tColumns;

if the channel parameter is the eigenvector of the channel matrix, the dimension of the eigenvector is represented as R × N_tWherein R represents the rank of the channel matrix.
A terminal device, comprising: the receiver, the processor and the transmitter,

the receiver is used for acquiring antenna configuration parameters and orthogonal base generation control parameters issued by a base station;

a processor, configured to generate at least two orthogonal bases according to the antenna configuration parameters and orthogonal base generation control parameters, where a configuration of each orthogonal base is related to an antenna configuration at a base station side;

the receiver is further configured to receive a downlink channel state information reference signal CSI-RS from the base station;

the processor is further configured to determine a channel parameter according to the CSI-RS, and select one of the at least two orthogonal bases as a target orthogonal base according to the channel parameter; and extracting a feedback parameter according to the channel parameter and the target orthogonal base,

and the transmitter is used for reporting the feedback parameters to the base station, wherein the number of the parameters of the feedback parameters is less than that of the channel parameters.
The terminal device of claim 19,

the antenna configuration parameters at least comprise one of the following parameters: the number of first-dimension antenna ports, the number of second-dimension antenna ports and configuration parameters of base station side polarized antennas; wherein the polarized antenna configuration comprises a single polarized antenna and a dual polarized antenna;

the orthogonal basis generation control parameter includes at least one of the following parameters: the number of the first dimension orthogonal bases, the number of the second dimension orthogonal bases and the number of the polarization direction dimension orthogonal bases.
The terminal device of claim 20,

if a base station side adopts a dual-polarized antenna, the orthogonal base is represented by multiplying a block diagonal matrix by a first unitary matrix, wherein each block matrix in the block diagonal matrix is a second unitary matrix, and the dimensionality of the second unitary matrix is N rows and M columns; the first unitary matrix is expressed as a kronecker product of a third unitary matrix with 2 rows and 2 columns and an identity matrix with M rows and M columns;

and if the base station side adopts a single-polarization antenna, the orthogonal base is represented as the second unitary matrix, wherein N represents the number of antenna ports in one polarization direction, and M is less than or equal to N.
The terminal device of claim 21,

if the antenna port on the base station side is configured to be a two-dimensional antenna port, the second unitary matrix is expressed as a kronecker product of a fourth unitary matrix and a fifth unitary matrix; wherein the fourth unitary matrix has a dimension of N₁Line M₁Columns, the dimension of the fifth unitary matrix is N₂Line M₂Column, N₁Representing the number of first dimension antenna ports in one polarization direction, N₂Represents the number of second dimension antenna ports in one polarization direction, and M₁≤N₁,M₂≤N₂。
The terminal device according to any of claims 20-22,

if the base station side adopts a dual-polarized antenna, the generated orthogonal base is represented as:

if a single-polarized antenna is adopted on the base station side, the generated orthogonal base is represented as:

wherein, B_(k,l,k'l',m)Represents an orthogonal base with the parameters k, l, k ', l', m, U_kAnd U_k'Respectively represent N₁×M₁Unitary matrix of, V_lAnd V_l'Respectively represent N₂×M₂Unitary matrix of, T_mDenotes a 2 × 2 unitary matrix, I denotes (M)₁M₂)×(M₁M₂) Represents a kronecker multiplication, and k, k' e {0,1, Λ O ∈₁-1},l,l'∈{0,1,ΛO₂-1}，m∈{0,1,ΛO₃-1}，O₁Denotes the number of first-dimension orthogonal bases, O₂Denotes the number of orthogonal bases of the second dimension, O₃The number of orthogonal bases in the polarization direction dimension is shown.
The terminal device of claim 23,

unitary matrix U_kIs shown as

Unitary matrix V_lIs shown as

Unitary matrix T_mIs shown as

Wherein, represents N_x×N_xOr inverse DFT matrix, i.e. expressed in particular as

Or,

the diagonal matrix is represented, specifically as:

or,

x belongs to {1,2,3}, and k is an integer, k is more than or equal to 0 and less than N_x。
The terminal device of claim 19, wherein the processor is specifically configured to:

projecting the channel parameters on each orthogonal basis to generate a projection matrix, projecting the at least two orthogonal bases to generate a group of projection matrices, wherein each projection matrix consists of S elements,

selecting L elements with larger values in each projection matrix, and calculating the sum of the values of the selected L elements with larger values;

comparing the sums of the calculated L larger element values in all projection matrices, and selecting the projection matrix with the largest sum of the L larger element values as the selected target orthogonal basis.
The terminal device of claim 19,

if the channel parameter is a channel matrix, the dimension of the channel matrix is represented as N_rLine N_tColumn (i) wherein N_tIndicates the total number of antenna ports on the base station side, N_rRepresenting the total number of antenna ports received by the terminal equipment;

if the channel parameter is a channel correlation matrix, the dimension of the channel correlation matrix is represented as N_tLine N_tColumns;

if the channel parameter is the eigenvector of the channel matrix, the dimension of the eigenvector is represented as R × N_tWherein R represents the rank of the channel matrix.
The terminal device of claim 19,

the processor is further configured to number all orthogonal bases;

the feedback parameters extracted by the terminal equipment comprise: the number of the target orthogonal base, the corresponding L larger element values in the target orthogonal base, and the position indexes of the L larger element values in the projection matrix.
A base station, comprising: a processor and a transmitter, wherein the processor is connected with the transmitter,

a processor, configured to set an antenna configuration parameter and an orthogonal basis generation control parameter, where the antenna configuration parameter at least includes one of the following parameters: the number of first-dimension antenna ports, the number of second-dimension antenna ports and configuration parameters of base station side polarized antennas; the orthogonal basis generation control parameter includes at least one of the following parameters: the number of the first dimension orthogonal bases, the number of the second dimension orthogonal bases and the number of the polarization direction dimension orthogonal bases;

and the transmitter is used for transmitting the antenna configuration parameters and the orthogonal basis generation control parameters to the terminal equipment through static or semi-static signaling.
The base station of claim 28, wherein the transmitter is further configured to send a downlink CSI-RS to the terminal device, so that the terminal device determines the channel parameters according to the CSI-RS.
The base station of claim 29, further comprising a receiver,

the receiver is configured to receive a feedback parameter reported by the terminal device, where the feedback parameter includes: the number of the selected target orthogonal basis, L larger element values projected on the target orthogonal basis, and projection position indexes corresponding to the L larger element values;

the processor is further configured to obtain the target orthogonal base according to the number of the target orthogonal base in the feedback parameter; acquiring L row vectors or L column vectors of the target orthogonal basis according to the projection position indexes corresponding to the L larger element values; and acquiring channel parameters according to the L larger element values and the L row vectors or the L column vectors.
The base station of claim 30, wherein obtaining the channel parameters further comprises: and generating a precoding matrix for the terminal equipment according to the channel parameters.
The base station according to claim 31 or 31,

if the base station side adopts a dual-polarized antenna, the target orthogonal base is expressed as:

if a single-polarized antenna is adopted on the base station side, the target orthogonal base is expressed as:

wherein, B_(k,l,k'l',m)Represents an orthogonal base with the parameters k, l, k ', l', m, U_kAnd U_k'Respectively represent N₁×M₁Unitary matrix of, V_lAnd V_l'Respectively represent N₂×M₂Unitary matrix of, T_mDenotes a 2 × 2 unitary matrix, I denotes (M)₁M₂)×(M₁M₂) Unit matrix of (2), representing gramsRogok multiplication and k, k' ∈ {0,1, Λ O₁-1},l,l'∈{0,1,ΛO₂-1}，m∈{0,1,ΛO₃-1}，O₁Denotes the number of first-dimension orthogonal bases, O₂Denotes the number of orthogonal bases of the second dimension, O₃The number of orthogonal bases in the polarization direction dimension is shown.
The base station of claim 32,

unitary matrix U_kIs shown as

Unitary matrix V_lIs shown as

Unitary matrix T_mIs shown as

Wherein, represents N_x×N_xOr inverse DFT matrix, i.e. expressed in particular as

Or,

the diagonal matrix is represented, specifically as:

or,

x belongs to {1,2,3}, and k is an integer, k is more than or equal to 0 and less than N_x。
The base station of claim 29,

if the channel parameter is a channel matrix, the dimension of the channel matrix is represented as N_rLine N_tColumn (i) wherein N_tIndicates the total number of antenna ports on the base station side, N_rRepresenting the total number of antenna ports received by the terminal equipment;

if the channel parameter is a channel correlation matrix, the dimension of the channel correlation matrix is represented as N_tLine N_tColumns;

if the channel parameter is the eigenvector of the channel matrix, the dimension of the eigenvector is represented as R × N_tWherein R represents the rank of the channel matrix.